1. Field of the Invention
The present invention relates to a multilayered electronic component having a coil conductor formed inside a laminate.
2. Description of the Related Art
An example of conventional multilayered electronic components is shown in FIGS. 13 and 14. This multilayered electronic component 100 is a chip inductor, and a coil conductor 102 is buried inside a laminate 101 having a rectangular parallelepiped shape. The coil conductor 102 includes a coil wiring pattern 104 formed on the surface of a ceramic layer 103 forming the laminate 101, and an electrical conductor (via conductor) 105 arranged on each ceramic layer 103 so as to extend therethrough in the thickness direction thereof. The coil conductor 102 functions as a coil by electrically connecting the end portions of each coil wiring pattern 104 by an electrical conductor 105.
An external extension of the coil conductor 102 is formed in the following manner. A terminal electrode 106 is provided at both ends of the laminate 101. An external extension electrode 107 is provided between the terminal electrode 106 and the end portion of the coil conductor 102. A plurality of the external extension electrodes 107 are provided, and each external extension electrode 107 is interlayer-connected via the electrical conductor 105 incorporated in the ceramic layer 103. The inner end of the external extension electrode 107 and the coil conductor 102 are electrically connected to each other via a connection wiring pattern 108 and the electrical conductor 105.
The connection wiring pattern 108 is provided on the surface of the ceramic layer 103 that is closest to the group of the ceramic layers on which the coil conductor 102 is formed. The connection wiring pattern 108 has a shape that connects a surface portion of the ceramic layer opposing the end portion of the coil conductor 102 to a surface portion of the ceramic layer opposing the external extension electrode 107.
The coil conductor 102 and the connection wiring pattern 108 are electrically connected to each other via the electrical conductor 105. The external extension electrode 107 and the connection wiring pattern 108 are electrically connected to each other via the electrical conductor 105. The external extension electrode 107 and the terminal electrode 105, which are arranged at the end portions of the laminate 101, are electrically connected to each other as a result of being brought into contact with each other.
In the configuration of the multilayered electronic component of Japanese Unexamined Patent Application Publication No. 11-260644 shown in FIGS. 13 and 14, there is a problem in that a plurality of patterns of the connection wiring pattern 108 are required. In general, the number of windings of the coil is adjusted in accordance with, for example, the required electrical characteristics. The adjustment of the number of windings in this case is performed by increasing or decreasing the number of the ceramic layers 103 on which the coil wiring pattern 104 is formed. When the number of the ceramic layers 103 is increased or decreased, the position at which the end portion of the coil conductor 102 is arranged changes. When the position at which the end portion of the coil conductor 102 is arranged changes, the shape of the connection wiring pattern 108 that connects the coil conductor 102 to the external extension electrode 107 must be changed.
For this reason, in the configuration of Japanese Unexamined Patent Application Publication No. 11-260644, the connection wiring pattern 108 having a shape different for each multilayered electronic component 100 having different characteristics must be formed on the ceramic layer 103. However, in this case, a plurality of form frames (masks) required to form each of the connection wiring patterns 108 become necessary. In that case, when a form frame is replaced, the form frame is cleaned, and the extra conductive paste is discarded. As a result, additional cleaning steps become necessary, and moreover, the amount of conductive paste to be discarded increases, causing the manufacturing cost to be increased correspondingly.
In this case, it is also possible to rotate and use the ceramic layer 103 on which the connection wiring pattern 108 is formed. In that case, since some type of indicator for identifying the direction of the ceramic layer 103 and rotating it becomes additionally necessary, the cost increases.
In the configuration of the known multilayered electronic component disclosed in Japanese Unexamined Patent Application Publication No. 2001-076928, although not shown in FIGS. 13 and 14, the connection wiring pattern 108 having a cross shape that connects together the arrangement positions of the end portions of the coil conductor 102 is formed. For this reason, it is possible to electrically connect each of the displaced end portions of the coil conductor 102 to one connection wiring pattern. However, in this configuration, as a result of the connection wiring pattern being formed in a cross shape, the area where the connection wiring pattern 108 blocks the internal space of the coil conductor 102 increases. This presents the problem that the electrical characteristics (inductance, etc.) of the multilayered electronic component decrease.